Ultrasonic relaxation will be employed to study the thermodynamics and kinetics of syn-anti glycosyl equilibrium in nucleosides and nucleotides in the free and bound states in solution: A. free solution conformations of: 1. 5'-AMP, 5'-ATP, 2'-deoxyadenosine to complement data already at hand; 2. 5'-GMP, 5'-Deoxy GMP, 3',5'-cyclic GMP - new information on guanosines; 3. Nucleoside antibiotics related to adenosine to establish if function-conformational relationship exists; 4. Dinucleoside monophates: ApU, UpA, GpC to see if syn-anti equilibrium still exists. B. Syn-anti conformational preferences as affected by: 1. Hydrogen bonding (5'-GMP - 5'-CMP); 2. Stacking to aromatic amino acids; 3. Bonding to antibiotics (2'-deoxy GMP with actinomycin).